...which fixes an issue encountered when compiling with Clang against trunk
libstdc++ (which contains pre-C++17-only code that triggers
<https://bugs.llvm.org/show_bug.cgi?id=41896> "Bogus 'error: no return statement
in constexpr function' when void return type is 'templated'")

Change-Id: I33368996c8ac8cf32893ba1b631ace2a606dafb1
Reviewed-on: https://gerrit.libreoffice.org/72409
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>